G-quadruplex Specific Thioflavin T-based Label-free Fluorescence Aptasensor for Rapid Detection of Florfenicol
Thioflavin T(ThT)can bind to G-quadruplex through non-covalent interaction to form G-quadruplex/ThT complex,showing strong fluorescence intensity,while free ThT fluorescence is very weak.In the presence of florfenicol(FF),the high affinity of the aptamer(Apt)with a G-quadruplex structure to the target enables the formation of the Apt/FF complex and the release of ThT,resulting in a decrease in fluorescence intensity.Based on this feature,this study designed a sensitive and rapid on-site detection system for the detection of florfenicol,a label-free fluorescent aptasensor based on G-quadruplex/thioflavin T.The detection range of this aptamer sensor was 0.0128-200 ng/mL,the actual detection limit was 0.0128 ng/mL,and the total detection time was 10 min.At the same time,the recovery rate of the actual spiked samples(milk and eggs)was calculated,and the spiked recovery rate was between 91.2%and 117.1%.The established label-free fluorescent aptasensor has the advantages of high specificity,low cost,and short time-consuming,and can be used for on-site detection of actual samples.